Heretofore, in mobile radio systems, automobiles equipped with receiving and/or transmitting equipment have required a special antenna. For example, it has been common to utilize an antenna unit which can be temporarily attached to the exterior of a rear trunk lid. While this may avoid permanently marring the finished exterior of the vehicle, it is a disadvantage that the antenna lead-in lacks a fixed secure path, and is subject to increased wear because of its exposed location. The drilling of a hole at the finished exterior of a luxury automobile is not an attractive alternative because of possible mechanical damage to the finish, increased susceptibility to corrosion, and the like. Furthermore, antennas as heretofore applied to existing vehicles have tended to detract from the originally designed aesthetic appearance.
It is believed that the motivation leading to a removable antenna has been not only ease of application and the avoidance of a permanent detraction from the aesthetic..appearance of the automobile, but also to enable removal of the antenna at times when vandalism to the antenna or theft of the radio unit was a particular danger.
The practice of mounting a mobile radio antenna on the window glass of an automobile and utilizing a capacitive coupling to an interior antenna lead-in is considered to be unsatisfactory because of unsightly appearance, obstruction to the window, the technical problems associated with the capacitive coupling, and the dangers of vandalism and accidental breakage.
It would be particularly desirable if a mobile radio antenna system could be devised which would fully harmonize with the intended aesthetic appearance of the automobile. Also of great utility would be an ornamental device which could serve as a mobile antenna when desired, but which would not be perceived by the public as an atenna, and thus would tend not to reveal the presence of a radio unit in the vehicle. An optimum result is achieved if an existing part of currently produced automobiles can be utilized as an effective mobile radio antenna. In this way, the antenna is a fully harmonized and intended feature of the aesthetic design and is installed during the original production process so as to insure against introducing problems of corrosion, wear, breakage and the like. If an ornamental device can be used as a mobile radio antenna, the presence of a mobile radio system may not be called to the attention of a potential wrongdoer even when such an ornamental device is retrofitted to existing automobiles. Further a frontally located non-obtrusive antenna may have utility in spacial diversity reception systems.